House Hacking Calculator
Live for free — or close to it. Analyze multi-family properties or roommate scenarios to see how rental income lowers your personal housing cost.
"True" cost subtracts monthly principal paydown (forced savings) from net expense. Negative = you're getting paid to live there.
How to Use the House Hacking Calculator
In under two minutes you’ll know your true net monthly housing cost, your cash-on-cash return, and whether your tenants could be covering your mortgage entirely.
Enter Purchase Price & Loan Details
Input the property purchase price, your down payment (as low as 3.5% for FHA), and your interest rate. The loan amount and monthly P&I are calculated automatically. Use the rate slider to quickly stress-test different rate environments.
Set Rental Income & Vacancy Rate
Enter the total gross monthly rent from all non-owner units. Apply a realistic vacancy rate (5–8% is typical) and an annual rent growth rate for projections. The calculator converts gross rent into effective income automatically, giving you a conservative real-world figure.
Add All Monthly Expenses
Fill in property tax, insurance, PMI or FHA mortgage insurance, and a monthly Repairs/CapEx budget (1% of purchase price annually is a common rule of thumb). Add HOA dues and your unit’s market rent — the amount you’d pay to rent an equivalent home — to unlock the annual savings comparison.
Review Results & Download the Report
The results panel instantly shows your net monthly cost, true cost after equity, cash-on-cash return, and Year 5 and 10 projections. Charts illustrate tenant versus owner coverage. Download the PDF report to share with your lender, real estate agent, or financial advisor.
What This Calculator Shows You
Most housing calculators only show your total monthly payment. This one shows what your tenants pay versus what you pay — and how that gap closes (or turns into profit) as rents grow over time.
Net Monthly Housing Cost
Your out-of-pocket monthly expense after effective rental income is subtracted from total PITI plus repairs and HOA. If this number is zero or negative, your tenants cover your full housing cost — and you may be living free or generating a profit.
“True” Cost After Principal Paydown
Each mortgage payment includes a principal component — money you keep as equity. Subtracting monthly principal paydown from your net cost gives the true economic cost of living there. A negative true cost means your total wealth is growing even while you pay housing costs.
Cash-on-Cash Return
Annual net cash flow divided by total cash invested (down payment plus estimated closing costs). A positive return means the property generates surplus income; a negative return means you’re still subsidizing housing costs — but often far less than renting the same area would cost.
Proportional Expense Breakdown Bars
Visual bars showing how each expense component (P&I, tax, insurance, PMI, CapEx, HOA) contributes to total monthly costs. Instantly see which items dominate your budget and where improvements — like eliminating PMI — would have the biggest impact.
Year 5 & Year 10 Net Cost Projections
As rents grow at your specified annual rate, your net housing cost decreases — even as mortgage expenses stay flat. The Year 5 and Year 10 projections quantify this improvement, showing the compounding benefit of house hacking over a longer hold period.
Downloadable PDF Report
A single-page professional report covering property inputs, monthly cost breakdown with proportion bars, and six summary cards: principal paydown, true cost, cash-on-cash return, annual savings versus renting, and Year 5 and 10 projections. Print-ready and shareable with agents and lenders.
House Hacking by the Numbers
Three House Hackers Who Should Run This Calculator
House hacking looks different depending on your property type, financial goals, and risk tolerance. These three profiles show when the strategy works best — and what to watch for in each scenario.
You’re buying your first home and a duplex in your target area pencils out: one side for you, one side to rent. With an FHA loan at 3.5% down, your tenant’s rent may cover 60–100% of your mortgage. The key tradeoff is FHA mortgage insurance — enter it accurately in the PMI field to see the true net cost. In many markets, house hacking a duplex is the only path to sub-$1,000/month housing in high-cost areas.
- Include FHA MIP (~0.55% of loan balance annually) in the PMI field for accurate results
- Use the calculator to confirm your net cost comfortably beats local rents before making an offer
- Budget the full 1% CapEx reserve — older multi-family properties have higher maintenance needs
You already have tenants — a basement unit, a garage apartment, or housemates — but you’ve never formally modelled whether it’s worth the hassle. Run your actual numbers through this calculator. You may discover your “true cost” is far lower than you realised, or that a rent increase to market rate would flip your net cost to zero. The projections may reveal the property is on track to cash-flow positively within a few years at current rent growth.
- Enter your actual current rent and compare to the market rent field to see if you’re undercharging
- Use the Year 5 projection to justify raising rents to market — show tenants the bigger picture
- Download the PDF as a baseline snapshot to track performance improvements year over year
You’re treating your primary residence as the foundation of a real estate portfolio. You’ll live in unit one, rent units two through four, build equity, and use the equity and rental history to qualify for the next property in two to four years. For this strategy, cash-on-cash return is less important than balance sheet growth and rental proof-of-income. The calculator’s equity and projection metrics matter most for your plan.
- Focus on the Annual Equity Built figure — this is the wealth engine that funds your next acquisition
- Use the Year 10 projection to model when the property crosses into strong positive cash flow post-move-out
- Keep repair reserves healthy — lenders scrutinise property condition when you refinance to pull equity
7 Things Every House Hacker Should Know Before Buying
House hacking is one of the most powerful wealth-building strategies available to owner-occupants — but the numbers need to work from day one. These tips help you model it accurately and avoid the common mistakes that turn a promising deal into a stressful one.
Always Model Vacancy — Never Assume 100% Occupancy
A common house hacking error is entering gross rent without accounting for vacancy. In practice, even in strong markets you’ll face a vacant month between tenants every one to two years. Use 5% as a floor and 8% in softer markets. The calculator automatically reduces your gross rent by the vacancy rate — this effective income figure is what you should build your budget around, not the gross figure on the lease.
The CapEx Budget Is Not Optional — Especially on Older Properties
Multi-family properties, particularly those built before 1980, carry significant deferred maintenance and capital expenditure risk. Roof replacement, HVAC systems, plumbing, and electrical upgrades are not unusual in the first five years of ownership. Budget 1% of purchase price annually at minimum — 1.5% for older properties — and enter that monthly figure in the Repairs/CapEx field. Ignoring it produces a net cost number that will feel optimistic the first time a major system fails.
Use “Your Unit Market Rent” Honestly for a Meaningful Savings Comparison
The annual savings figure compares your net housing cost to what you’d pay to rent an equivalent unit in the same market. To make this comparison meaningful, enter the actual market rent for a comparable home — not an aspirational or conservative figure. If market rent for your area is $2,200/month, enter $2,200. This shows the true opportunity cost of renting versus house hacking, which is often the most compelling number in the entire analysis.
FHA Mortgage Insurance Changes the Math — Enter It Separately
FHA loans require upfront MIP (1.75% of the loan amount, typically rolled into the loan) and ongoing annual MIP (~0.55% of the remaining balance for most 30-year loans, paid monthly). On a $430,000 FHA loan, that’s approximately $197/month in ongoing MIP. Enter this in the PMI field to see an accurate net cost. Conventional loans cancel PMI at 20% equity — FHA loans (originated after 2013 with less than 10% down) carry MIP for the life of the loan, which significantly affects long-run economics.
The Rent Growth Rate Is Conservative by Default — Adjust for Your Market
The default 3% annual rent growth is a reasonable national average but may significantly understate or overstate growth in your specific market. High-demand urban markets have historically seen 4–6% annual rent growth over long periods. Slower growth markets may be closer to 2%. Run both scenarios using the projections to understand the range of outcomes over your hold period. The Year 10 projection in particular is highly sensitive to the growth rate assumption.
A Slightly Negative Cash-on-Cash Is Not a Failed Deal
Many excellent house hacks produce a small negative cash-on-cash return in year one — meaning you’re still paying something out of pocket, just far less than market rent. The true measure of success is the “true cost” figure (net cost minus principal paydown) and the trajectory shown in Year 5 and Year 10. A deal that costs $300/month net today and generates positive cash flow by Year 5 is not a failure — it’s a calculated subsidy for a compounding asset.
Download the PDF and Bring It to Every Lender and Agent Meeting
The PDF report presents your analysis in a professional, shareable format that demonstrates you’ve done rigorous pre-purchase modelling. Lenders appreciate seeing that borrowers understand the full cost picture — including vacancy, CapEx, and PMI — rather than relying on gross rent alone. Agents who see you’ve run the numbers properly will take your offers more seriously. The report is also a useful personal baseline to revisit each year and compare against actual performance.
Frequently Asked Questions
Everything you need to know about how house hacking works, how this calculator models it, and how to interpret every output figure.
Important disclaimer: All results produced by the House Hacking Calculator are estimates for educational and planning purposes only and do not constitute financial, legal, real estate, or mortgage advice. This calculator models a simplified one-year snapshot of cash flow and does not account for income tax treatment of rental income, depreciation deductions, local landlord regulations, rental income underwriting limits, property appreciation, or inflation on expenses. Actual results will vary materially based on local market conditions, property condition, tenant behaviour, financing terms, and tax circumstances. Always review your figures with a licensed mortgage professional, CPA, and qualified real estate agent or attorney before making any purchase or investment decision. HomeExpertly is not a lender, broker, financial advisor, or tax professional.